6639967980 has 192 divisors, whose sum is σ = 22058910720. Its totient is φ = 1654152192.

The previous prime is 6639967931. The next prime is 6639967991. The reversal of 6639967980 is 897699366.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 527844 + ... + 540276.

It is an arithmetic number, because the mean of its divisors is an integer number (114890160).

Almost surely, 2^6639967980 is an apocalyptic number.

6639967980 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6639967980, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (11029455360).

6639967980 is an abundant number, since it is smaller than the sum of its proper divisors (15418942740).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

6639967980 is a wasteful number, since it uses less digits than its factorization.

6639967980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12517 (or 12509 counting only the distinct ones).

The product of its (nonzero) digits is 26453952, while the sum is 63.

The square root of 6639967980 is about 81485.9986746189. The cubic root of 6639967980 is about 1879.5562537263.

The spelling of 6639967980 in words is "six billion, six hundred thirty-nine million, nine hundred sixty-seven thousand, nine hundred eighty".